millennia list

A-list

The A-list is part of a larger guide called The Hot List that has become an industry-standard guide in Hollywood. Lesser-known actors inhabit the B+, B, and C lists, and there is even a dreaded "Bottom of the Heap," or "Z-List." James Ulmer has also developed a Hot List of directors.

Ulmer Scale

The list was created by veteran entertainment journalist James Ulmer, who developed a 100-point method to quantify a star's value to a film production, in terms of getting a movie financed and the cameras rolling. The Ulmer Scale also takes into account an actor's history (box office successes vs. failures), versatility, professional demeanor, and ability and willingness to travel and promote movies.

In the UK, the term "Z-list" is used for people with very limited fame, such as reality TV contestants, or former celebrities who are no longer in the limelight.
Also, "Z-list" celebrities can be people who might star on Broadway musicals, giving them limited fame as well.